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Hi Everyone, need a little help choosing the right flattener/reducer for the William Optics Zenithstar73.

 I am after one that does both jobs so that rules out the dedicated Flat73 which is just a flattener!

So I was wondering if I could get away with the Flat6 0.8 reducer which does say it works on scopes 70 - 80mm f/6  but doesn't list the ZS73 in the models list or do I need to spend the extra and get the Flat6A11?

Can anyone shed some light on this have email 365 where I have seen the Flat6 but had no reply.

Thanks in advance.

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Hi. I have a GT71 triplet and when I ordered from RVO I had requested the dedicated flattener/reducer as well. When it arrived the box had been packed with the newer Flat6A II. I'm guessing the older ones are discontinued now. The flat6A is good but you need to play around with the adjustability to get best results. Mine is pretty close, after trial and error it's only 0.55mm off the recommended 9.3mm (8.75mm on mine) but when you factor in a light pollution filter and glass in front of the sensor, it's probably spot on as glass increases back focus. Try an email to FLO with regards to compatibility as you'll usually get a same day response. Emails to 365, well, not as prompt...

 

Or straight to the source:

wo@williamoptics.com

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Thanks David, I could only find the flat6A on 365 for £149 hence the email to them, no where else seems to stock it! So as you say it may have been discontinued the Flat6AII is only another £20 so will contact FLO and see if it's compatible as it doesn't seem to list the ZS73 in the models list. 

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50 minutes ago, Ulysses31 said:

So as you say it may have been discontinued the Flat6AII is only another £20 so will contact FLO and see if it's compatible as it doesn't seem to list the ZS73 in the models list. 

The Flat 6A11 is a nice bit of kit as it has built in adjustment so saves messing about with spacers.

Dave

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OK guys so managed to get hold of someone at WO and it seems they have played with a few different designs but haven't made a dedicated reducer for the ZS73  as they feel it's perfect as it is! Hence just the Flat73 flattener, the Flat6a has been discontinued and the Flat6aii will not work with full frame sensors. Although they did say it may with a bit of adjustment work with cropped sensors i.e. APS-C. The Altair 0.8 reducer apparently may work with this but you will have to play around to get it spot on. 

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